:root {
  --line-border-fill: #3498db;
  --line-border-empgty: #e0e0e0;


}

* {
  box-sizing: border-box;
}

body {
  background-color: #f6f6f6;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  overflow: hidden;
  margin: 0;
}

.container {
  text-align: center;

}

.progress_cont {
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
  margin-bottom: 30px;
  max-width: 100%;
  width: 350px;

}
.progress_cont::before {
  content: "";
  position: absolute;
  background-color: var(--line-border-empgty);
  top: 50%;
  left: 0;
  /* transform: translate(-50%, -50%); */
  transform: translateY(-50%);
  height: 4px;
  width: 100%;
  z-index: -1;
}
.progress {
  background-color: var(--line-border-fill);
  position: absolute;
  top: 50%;
  left: 0;
  transform: translateY(-50%);
  height: 4px;
  width: 0%;
  z-index: -1;
  transition: all 0.3s ease-in-out;  /* 过渡效果  */
}
.circle{
  background-color: #fff;
  color: #999;
  border-radius: 50%;
  height: 30px;
  width: 30px;
  display: flex;
  justify-content: center;
  align-items: center;
  border: 3px solid var(--line-border-empgty);

}
.circle.active {
  border-color: var(--line-border-fill);
}
.btn:active { /* 按钮按下样式 */
  transform: scale(0.8);
}
.btn:focus { /* 按钮聚焦样式 */
  outline: 0;
}
.btn:disabled {
  background-color: var(--line-border-empgty);
  cursor: not-allowed;
}
.btn {
  background-color: var(--line-border-fill);
  color: #fff;
  width: 100px;
  height: 30px;
  border: none;
  border-radius: 10px;
  cursor: pointer;
}